Slope aspect affects the non-structural carbohydrates and C:N:P stoichiometry of Artemisia sacrorum on the Loess Plateau in China

- We analyse the effects of slope aspect on forb and soil properties.
- The slope aspect affected the biomass and its allocation on Artemisia sacrorum.
- The slope aspect had different effects on plant and soil carbon: nitrogen: phosphorus stoichiometry.
- The slope aspect affected the concentrations of non-structural carbohydrates and their allocation in Artemisia sacrorum.
- In arid environments slope aspect was a main environmental factor that drives plant nutrient and stoichiometry dynamics.

Slope aspect, as an important topographic factor on the Loess Plateau in China, may influence the productivity and relative characteristics of Artemisia sacrorum in this area. Three slope aspects (sunny, half-sunny, and shady slopes) were chosen to study the effects of slope aspect on the biomass, carbon:nitrogen:phosphorus (C:N:P) stoichiometry, and non-structural carbohydrate (NSC) concentrations in A. sacrorum in 2014. The maximum A. sacrorum biomass was detected in the half-sunny slope, and the ratio of belowground to aboveground biomass significantly changed in the different slope aspects. Slope aspect significantly affected the N:P ratio in the aboveground and the C:P and N:P ratios in the belowground. The maximum C:P and N:P ratios in the rhizosphere and non-rhizosphere soils were reached in the sunny slope, whereas no significant change was observed in C:N ratio. The maximum NSC concentrations occurred in different A. sacrorum tissues, that is, aboveground in the sunny slope and belowground in the half-sunny slope. The ratio of soluble sugar to starch concentrations in the aboveground significantly differed among the three slope aspects, but that in the belowground showed no significant difference. Slope aspect was the main environmental factor affecting the plant nutrient and stoichiometry on the Loess Plateau in China.